Leake, who never travelled around the east end of the lake, made up his mind that Thermon must be found at Vlocho, the most impressive ruin and strongest fortified place in Ætolia, not far east of Agrinion. Starting with this as a fact, he laid out the rest of the topography accordingly. Two great difficulties, however, confronted Leake. Polybius speaks of the lake as covering the left of the army during a considerable part of the march, while Leake, placing Thermon at Vlocho, cannot keep them from leaving it well to their right all the way. The great topographer, who had successfully located Calydon by transposing two passages in Strabo and inserting a negative, thought it not venturesome to "restore" right for left in this passage of Polybius, on the ground that there are many occurrences of such slips in ancient writers. A second difficulty troubled him less. A march from the Acheloos to Thermon, which is spoken of as a forced march, a record march if you will, from the dawn of a summer day till late in the afternoon, by hardy troops, cannot, if Vlocho is Thermon, be spun out to more than fifteen miles, and that mostly over good ground. Leake talks loosely of arrival at two o'clock in the afternoon, which hardly does justice to the πολλῆς ὥρας of the text. The prestige of Leake, his almost established record of never going astray, led topographers generally to follow him, at least in the location of Thermon. Bazin, indeed, having a conscience about changing left to right, makes Philip march clear round the lake and reach Vlocho in season to destroy that great citadel on the same day, a distance of forty-five miles over some very bad ground, and that, too, on top of a forced march the day before. A military man like Leake could not have made this error, though he led Bazin into it by falsely locating Thermon.